i.MX6Q has a 64-bit SoC unique ID stored in OCOTP, it can be used
as SoC serial number, see below example:
root@imx6qpdlsolox:~# cat /sys/devices/soc0/serial_number
240F31D4E1FDFCA7
Signed-off-by: Anson Huang <[email protected]>
---
arch/arm/mach-imx/cpu.c | 30 +++++++++++++++++++++++++++++-
1 file changed, 29 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mach-imx/cpu.c b/arch/arm/mach-imx/cpu.c
index 0b137ee..3293c1d 100644
--- a/arch/arm/mach-imx/cpu.c
+++ b/arch/arm/mach-imx/cpu.c
@@ -1,15 +1,20 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/err.h>
+#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
+#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/sys_soc.h>
#include "hardware.h"
#include "common.h"
+#define OCOTP_UID_H 0x420
+#define OCOTP_UID_L 0x410
+
unsigned int __mxc_cpu_type;
static unsigned int imx_soc_revision;
@@ -76,9 +81,13 @@ void __init imx_aips_allow_unprivileged_access(
struct device * __init imx_soc_device_init(void)
{
struct soc_device_attribute *soc_dev_attr;
+ const char *ocotp_compat = NULL;
struct soc_device *soc_dev;
struct device_node *root;
+ struct regmap *ocotp;
const char *soc_id;
+ u64 soc_uid = 0;
+ u32 val;
int ret;
soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
@@ -128,6 +137,7 @@ struct device * __init imx_soc_device_init(void)
soc_id = "i.MX6SX";
break;
case MXC_CPU_IMX6Q:
+ ocotp_compat = "fsl,imx6q-ocotp";
soc_id = "i.MX6Q";
break;
case MXC_CPU_IMX6UL:
@@ -153,18 +163,36 @@ struct device * __init imx_soc_device_init(void)
}
soc_dev_attr->soc_id = soc_id;
+ if (ocotp_compat) {
+ ocotp = syscon_regmap_lookup_by_compatible(ocotp_compat);
+ if (IS_ERR(ocotp))
+ pr_err("%s: failed to find %s regmap!\n", __func__, ocotp_compat);
+
+ regmap_read(ocotp, OCOTP_UID_H, &val);
+ soc_uid = val;
+ regmap_read(ocotp, OCOTP_UID_L, &val);
+ soc_uid <<= 32;
+ soc_uid |= val;
+ }
+
soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%d.%d",
(imx_soc_revision >> 4) & 0xf,
imx_soc_revision & 0xf);
if (!soc_dev_attr->revision)
goto free_soc;
+ soc_dev_attr->serial_number = kasprintf(GFP_KERNEL, "%016llX", soc_uid);
+ if (!soc_dev_attr->serial_number)
+ goto free_rev;
+
soc_dev = soc_device_register(soc_dev_attr);
if (IS_ERR(soc_dev))
- goto free_rev;
+ goto free_serial_number;
return soc_device_to_device(soc_dev);
+free_serial_number:
+ kfree(soc_dev_attr->serial_number);
free_rev:
kfree(soc_dev_attr->revision);
free_soc:
--
2.7.4